8-channel, 24-bit GX1278 hardware and software replaces TI ADS1278 for vibration and modal analysis

Vibration modal analysis is a technique used to determine the vibration characteristics of the structure, widely used in the engineering field to avoid resonance and optimize the design, vibration and modal analysis as a key means of assessing the health of the structure and the dynamics of the structure, to provide accurate insight into the vibration behavior of the structure, and to effectively predict the potential failure. In this process, high-performance data acquisition and conversion is a very critical device, this paper recommends the use of 8-channel 24-bit GX1278 applied to vibration and modal analysis.

The GX1278 hardware and software 100% replacement of the TI ADS1278, support for 8-channel 24-bit, synchronous sampling, the chip can be based on the speed, accuracy and power consumption needs, from the four modes to choose from:

1, high-speed (HS) mode, the fastest speed, with 37MHz clock up to 144kSps, -3dB bandwidth 70kHz.

2、High-precision(HR)mode，the highest precision, SNR up to 111.7dB, THD up to -122.9dB, power consumption only 20.8mW/channel;

3. Low Power (LP) mode, with the same output rate as HR mode, but with power consumption almost halved; and Low Speed (LS) mode, for low-speed acquisition, with power consumption as low as 2.7mW/channel. 

The GX1278 is easy for developers to use because it is controlled directly using the PIN pin, eliminating the need to compile registers. It uses a high-order multi-bit Delta-sigma modulator that shapes the in-band noise and then filters it through an on-chip digital extraction filter, resulting in very low in-band noise power. The features are as follows:

- 8-channel synchronized sampling with data rates up to 144kSps 

- High-bandwidth FIR filters and low-latency SINC filters optional 

- Low power consumption: HS mode: 34.0mW/channel;

HR mode: 20.8mW/channel;

LP mode: 10.9mW/channel;

LS mode: 2.7mW/channel;

- Rail-to-Rail Input Common Mode Level

- Common mode rejection ratio: 116dB

- Analog power supply 5V; Digital power supply 1.8V

- IO power supply: 1.8V~3.3V

- SPI or frame synchronization interface, support daisy chain mode

- ESD level: HBM ±2kV, CDM ±2kV; Latch-up ±600mA

- Operating temperature range: -40°C to +85°C